Dry friction clutches are often utilized to allow for selective engagement of an engine with an input shaft of a transmission. Many dry clutches have a cover that is spaced from and connected with an engine flywheel. Inside the cover is a pressure plate that is torsionally connected to the cover and is axially moveable towards the flywheel. Positioned between pressure plate and flywheel is a friction disc. The friction disc is torsionally connected with an input shaft of a transmission. To urge the pressure plate towards the flywheel to capture the friction disc with the flywheel, there is an apply spring or spring loaded lever. As the friction lining of the friction disc wears, adjustment is required. To provide for adjustment, many clutches have a multiple cam ring adjuster between the apply spring or lever and the pressure plate. Many of the adjuster arrangements have a first cam ring that is non-rotative that engages a second rotative ring. A torsional spring is provided to urge the second cam ring to rotate with respect to the first cam ring. As the second cam ring rotates, the distance between the apply spring or lever and an extreme end of the pressure plate increases to compensate for the friction plate wear.
Examples of dry friction clutches with cam ring adjustment mechanisms can be found by a review of U.S. Pat. Nos. 5,964,429 and 6,109,412 and 6,292,099. It is also desirable in dry friction clutches with adjustment mechanisms to limit the maximum amount of adjustment. The friction material linings of the friction disc are typically attached to a steel backing plate by recessed rivets. Over adjustment of the pressure plate can allow the pressure plate to force the rivets of a worn friction disc into the engine flywheel causing undesired damage. It is desirable to provide an adjustment limiting feature that can be modified for clutch friction discs having different lining thicknesses or different desired maximum adjustment without extensive redesign of the clutch or the clutch adjustment mechanism. It is also desirable to provide an adjustment mechanism for a dry friction clutch wherein a baffle that protects a torsional spring between first and second cam rings can be easily assembled to the second cam ring without the utilization of tools, and wherein the baffle can be utilized in piloting a position of a second cam ring with respect to a first cam ring. It is also desirable for a baffle to be a secondary device to prevent dislodgement of a torsional spring from the first cam ring.
Other advantages of the present invention will become more fully apparent from a review of the invention as it is provided in the detailed description.